CN110072568B

CN110072568B - Blood treatment device for performing an extracorporeal blood treatment, blood guiding device, blood treatment system

Info

Publication number: CN110072568B
Application number: CN201780077600.XA
Authority: CN
Inventors: J·克勒温豪斯
Original assignee: Fresenius Medical Care Deutschland GmbH
Current assignee: Fresenius Medical Care Deutschland GmbH
Priority date: 2016-12-15
Filing date: 2017-12-14
Publication date: 2022-02-22
Anticipated expiration: 2037-12-14
Also published as: US11433173B2; EP3554578A1; DE102017210134A1; US11707560B2; US20200069859A1; WO2018109071A1; CN110072568A; WO2018109070A1; DE102017216689A1; CN110072569A; US20200069860A1; CN110072569B; EP3554577A1

Abstract

The invention relates to a blood treatment device for performing an extracorporeal blood treatment, in which blood is conducted in a blood conducting device having a main blood line and at least one secondary line, wherein the main blood line has a dialyzer and a blood treatment element downstream of the dialyzer, while the blood treatment device also has a control device equipped for generating a blood flow in the main blood line and the secondary line, and a pump arrangement, wherein the control device is configured such that the pump arrangement can be operated such that a first blood flow rate in the dialyzer is decoupled from a second blood flow rate in the blood treatment element. The invention also relates to a blood guiding device for cooperation with a blood treatment device and a blood treatment system.

Description

Blood treatment device for performing an extracorporeal blood treatment, blood guiding device, blood treatment system

Technical Field

The present invention relates to a device for performing an extracorporeal blood treatment, a blood guiding device for cooperation with a blood treatment device and a blood treatment system.

Background

In the field of extracorporeal blood treatment, it is known that various different therapies can be combined in a single treatment which can be performed, for example, by means of a single medical device and/or a single medical system. In other words, by using at least two separate blood treatment elements in the combined extracorporeal blood circulation, the drawn blood is preferably treated in various different ways. This therapy is called combination therapy. Therapies often combined with medical indications that are causally related and therefore frequently occur in combination. Furthermore, when the treatment techniques prove necessary to combine them in this way due to a favourable synergistic effect, it is also advisable to apply a combination therapy to the various indications.

Thus, for example, a combination of kidney replacement therapy with other extracorporeal blood therapies is used in the field of extracorporeal blood treatment. For example, treatment of acute dialysis (CRRT), such as Hemodialysis (HD), Hemodiafiltration (HDF), Hemofiltration (HF), Hemoperfusion (HP), or ISO-UF, with extracorporeal membrane lung oxygenation and/or CO removal₂In combination with the treatment of (a) is used in conjunction with extracorporeal blood circulation. In most cases, a dialyzer and a blood treatment element, for example a gas exchanger, for another extracorporeal blood treatment are therefore arranged in series in the combined extracorporeal blood circuit.

Furthermore, the efficacy of gas exchange is known, in particular for removing CO from blood₂Or for enriching blood with O₂The efficacy of (c) increases with increasing flow rate.

The inventors have realized that the inevitable coupling of the flow rate in the dialyzer and the flow rate in the gas exchanger is problematic due to the series arrangement of these two components independent of their order, and therefore problematic for operating the treatment device with efficient gas exchange. For example, the flow rates used in continuous treatment methods for acute dialysis (CRRT) typically do not exceed 200-300 mL/min. However, the efficiency of the above-described pulmonary support therapy depends to a large extent on the blood flow rate. In the case of Extracorporeal Membrane Oxygenation (ECMO), the Oxygenation rate may approach zero at blood flow rates less than 500 mL/min. Therefore, pure ECMO methods typically use blood flow rates significantly greater than 1L/min. CO removal at even lower blood flow rates₂However, the range generally used herein is only above about 500 mL/min. Thus, the combination of these renal replacement therapies and pulmonary support therapies in the prior art has always been associated with the following facts: one of the basic indications is being treated with reduced efficiency.

However, the above-mentioned problems are not limited to the combination of renal replacement therapy and pulmonary support therapy, but are always encountered whenever the dialyzer is operated in combination with a blood treatment element for extracorporeal blood treatment in an extracorporeal blood circuit, wherein the dialyzer and the blood treatment element respectively have different requirements on the blood flow rate for obtaining an optimal treatment rate.

Disclosure of Invention

The object of the present invention is to overcome the above-mentioned disadvantages and to allow extracorporeal blood treatment using a combination of a dialyzer and another blood treatment element (combination therapy) within the optimal efficiency range of each partial therapy.

According to the invention, this object is achieved by an apparatus according to the independent claim. The dependent claims additionally contain advantageous embodiments of the invention, respectively.

According to the invention, a blood treatment device for performing an extracorporeal blood treatment is provided, in which blood is passed through a blood conducting device having a main blood line and at least one secondary line which is fluidically connected to the main blood line, wherein the main blood line has a dialyzer and a blood treatment element located downstream of the dialyzer, the blood treatment device further having a control device and a pump arrangement which is equipped for generating a blood flow in the main blood line and the at least one secondary line, wherein the control device is configured such that the pump arrangement can be operated such that a first blood flow rate in the dialyzer (dialyzer flow rate) is decoupled from a second blood flow rate in the blood treatment element.

The blood conducting device according to the invention for cooperation with the blood treatment device according to the invention has: a main blood line for fluid connection to a dialyzer and for fluid connection to a blood treatment element downstream of the dialyzer, wherein the main blood line has a blood sampling port at one end for connection to a blood draw circuit of a patient and a blood return port at the other end for connection to a blood return circuit of the patient; at least one secondary line leading from the primary blood line at a first branch point and rejoining the primary blood line at a second branch point; and one or more pump arrangement sections which are formed for the action of the pump arrangement of the blood treatment device.

The blood treatment system according to the invention has a blood treatment device according to the invention and a blood conducting device according to the invention.

In other words, the blood treatment device according to the invention and the blood conducting device and the blood treatment system according to the invention make it possible to improve the operation of an extracorporeal blood treatment in terms of treatment efficiency, using a common extracorporeal blood circuit and connecting a dialyzer in series with a blood treatment element for another extracorporeal blood treatment, which is arranged downstream of the dialyzer. For this additional extracorporeal blood treatment, a higher blood flow than the one used for the treatment in the dialyzer is suitable.

The blood treatment member for additional extracorporeal treatment may be for O enrichment₂And/or CO removal₂The gas exchange unit of (1). The blood treatment element may also be a sorbent cartridge for therapeutic plasmapheresis. The blood processing component may also be a diagnostic component that can determine a parameter of the blood to detect the presence of a pathological change in the blood. All treatment elements acting on the blood may represent blood treatment elements in the sense of the present description. The action may be mechanical, chemical, physical or other.

In the sense of this specification, "treatment" may include not only curing, but also at least relief, symptomatic treatment, delay, drug withdrawal and diagnosis. In particular, blood treatment may be understood to include any effect on blood or blood changes, such as adding or removing substances to or from blood that may cause one of the above effects or a corresponding effect.

The use of a combined extracorporeal blood circulation for both treatments is advantageous in the sense of a combined theory, since then the invasive steps of blood withdrawal and blood return of the two treatments have to be performed only once, and therefore the patient is exposed to the associated treatment risks only once.

There can basically be two sequences when the dialyzer and the blood treatment element are arranged in series in the extracorporeal blood circulation. However, if the blood first flows through the gas exchanger and then through the dialyzer, for example, CO is removed as an additional extracorporeal blood treatment₂In the case of (2), then through the gas exchangerAfter having passed through the gas exchanger already with low CO₂Blood levels may experience CO₂And (5) re-enriching. This is achieved due to the concentration gradient across the membrane of the dialyzer, since the dialysis solution usually contains bicarbonate, of which CO₂In a buffered form. This re-enrichment does not occur if the blood passes through a gas exchanger downstream of the dialyzer.

The blood processing device may represent a reusable machine side of the blood processing system. The blood conducting device can form a set of blood lines, or a cassette with blood lines, or a combination of blood lines and at least one cassette with blood lines for equipping the blood treatment device. The blood conducting device here can be designed as a disposable medical product, which is discarded after each treatment for hygienic reasons. In particular, the blood conducting device may have, in addition to the blood conducting structure, one or more additional fluid conducting structures, such as a dialyzer circulating structure or a line for conducting a purge gas during operation of the gas exchanger.

The main blood line of the blood guiding device may have suitable connectors or connection structures for connection to a dialyzer and/or for connection to a blood treatment element. The design of these connectors, in particular for connection to a dialyzer, may comprise, for example, a cylindrical shape with an outer diameter in the range of 10.5-12.8mm and a conical fluid channel with an inner diameter of 6.33mm at the distal end of the connector. However, other embodiments satisfying the requirements of the desired flow rate according to the knowledge of the person skilled in the art are also conceivable according to the invention. Furthermore, when the blood guiding device is connected to the main blood line, for example by adhesive bonding or welding, the blood guiding device may further comprise a dialyzer and/or a blood treatment element.

The blood treatment device according to the invention and the blood conducting device according to the invention may be arranged to work together, which may together form a blood treatment system according to the invention. In addition to the blood treatment device and the blood conducting device, the blood treatment system may also comprise other components.

The devices for blood treatment and blood guidance may each have some mating means for cooperation. Thus, for example, the blood treatment device has a pump arrangement, while the blood conducting device has one or more pump arrangement sections designed for acting on the pump arrangement of the blood treatment device.

Alternatively, the blood treatment device in some embodiments may have one or more pressure sensors, or in some embodiments the blood conducting device may optionally have one or more pressure measuring sections, which may be designed for determining the pressure by means of the pressure sensors of the blood treatment device for measuring the pressure described above. The pressure measurement section may be a flexible membrane or a branch line that may transmit the pressure in the blood guiding device to the pressure sensor through a compressible gas column.

Furthermore, in some embodiments, the blood processing device may optionally have one infusion pump for supplying a medical fluid or two infusion pumps for supplying a medical fluid or three infusion pumps for supplying a medical fluid or four or more infusion pumps for supplying a medical fluid, while in some embodiments the main blood line of the blood conducting device may optionally have one or more injection ports for anticoagulated medical fluid and optionally one or more injection ports for diluting fluid.

An injection port here may be understood as a simple connector to the main blood line of the blood-conducting device, for example designed as a luer lock, but may also be an access line which is releasably or fixedly connected to the main blood line. The infusion pump of the above blood processing apparatus may be provided for having a pumping action on the access line connected to the injection port. The access lines may each be connected to a fluid reservoir with an added fluid for conveying said fluid into the main blood line by means of an infusion pump.

In one embodiment, the inventors propose that the main blood line of the combined extracorporeal blood circulation should branch off at a first branch point upstream of the dialyzer, that the second line should be led around the dialyzer and should join the main blood line again at a second branch point located downstream of the dialyzer and upstream of the gas exchanger. In this way it is possible to obtain,the inventors have placed the dialyzer in the main blood line upstream of the gas exchanger. Thus, the above-mentioned CO can be prevented₂Is re-enriched.

Furthermore, a pump system can be provided on the extracorporeal blood circulation, which pump system is equipped to generate a blood flow in the primary and secondary blood lines. For this purpose, the pump system may be connected to a control device. The control device is configured to control the operation of the pump system by a corresponding signal. The term "control" also refers to the possibility of regulation as an alternative in the sense of the entire specification.

The control device is configured to operate the pump system such that a first blood flow rate in the dialyzer is decoupled from a second blood flow rate in the blood treatment element. The term "decoupled" is understood here to mean that any desired flow rate can be generated in the dialyzer and the blood treatment element by means of the control device, without limiting the choice of other flow rates.

In other embodiments, the pump system may be designed to produce blood flow rates in the primary and secondary lines that are independent of each other. The term "independent" is here understood to mean that the selection of one of these two flow rates has no influence on the setting of the pump system to select the other flow rate.

Those skilled in the art will recognize that the pump system may be designed in various ways to function in the manner described above.

Typically, the pump system has at least two elements acting on the flow in two line sections. At least one of these elements is usually an active element, by means of which a flow can be induced in a line element (for example a pump). The second of the at least two elements may also be an active element for generating a flow or a passive element whose effect may include that the flow is defined or adjustable by the element. The second element may be, for example, a throttle structure or a valve.

For example, the pump system may include an occlusion blood pump located in the main blood line upstream of the first branch point and an additional occlusion blood pump located downstream of the first branch point and upstream of the dialyzer. Additional exemplary embodiments of the pump system are included in the drawings and description of the drawings. However, in addition to the embodiments described here as examples, the invention also encompasses all other pump systems capable of carrying blood through the primary blood line and/or the at least one secondary line.

In additional embodiments of the present invention, the pump system may also be equipped to generate a blood flow in the secondary line. In this case, the control device may be configured to operate the pump system such that the blood flow rate in at least one section of the primary blood line is independent of at least one of the blood flow rates in the respective secondary lines.

In another embodiment, the main blood line associated with the extracorporeal blood circulation branches off at a first branch point located downstream of the blood treatment element for additional extracorporeal blood treatment, and the secondary line is routed around the blood treatment element and is again joined to the main blood line upstream of the blood treatment element and downstream of the dialyzer. In this case, the pump system utilizes the blood flow in the secondary line to create recirculation of the blood flow through the blood processing component. The blood flow rate in the blood treatment element is increased by the blood flow in the secondary line compared to the blood flow rate in the dialyzer, which according to the invention decouples the two flow rates, thereby solving the problem.

In the removal of CO₂In the case of extracorporeal blood, the passage of the extracorporeal blood through the gas exchanger first of all reduces the free available CO in the plasma₂. Next, free CO₂Natural CO from blood again₂The buffer system discharges into the plasma. Thus, free CO is compensated after a period of time₂An additional reduction in partial pressure. The inventors have realized that blood that has been treated in the gas exchanger may thus be reprocessed after a short time, and it may therefore be worthwhile to recirculate the blood through the gas exchanger, as described above.

In an additional embodiment of the invention, the blood can also be passed through two secondary lines, wherein the first secondary line is separated from the main line at a first branch point upstream of the dialyzer and is again joined to the main blood line at a second branch point downstream of the dialyzer and upstream of the treatment element. The secondary line may branch from the main blood line at a recirculation branch point downstream of the blood treatment element and lead to a recirculation return port. The recirculation return port can here be arranged in the main blood line upstream of the connection point for the blood treatment element and downstream of the connection point for the dialyzer. Furthermore, the recirculation return port may also be disposed in the first secondary line upstream of the second branch point. In these embodiments, the secondary line may recirculate blood through the blood processing component for additional blood processing treatment, possibly contributing to an increase in the efficiency of that portion of the treatment. In these embodiments, the pump arrangement may also be equipped to generate a blood flow in the secondary line. Furthermore, the control device may be configured to operate the pump configuration such that the blood flow rate in at least one section of the primary blood line is independent of at least one of the blood flow rates in the respective secondary lines.

In extracorporeal blood treatment, measures may be taken to counteract the coagulation of blood. For this purpose, patients are usually treated systemically with anticoagulant substances such as heparin, or local anticoagulation can be administered in the extracorporeal blood circulation, for example by means of heparin or by addition of citrate and calcium (Ci-Ca anticoagulation). Anticoagulant coatings on blood-carrying members of extracorporeal blood circulation are also widely used. Methods using Ci-Ca anticoagulation have been used for many years in the field of acute dialysis, where the dose has been optimized and extensively evaluated in long-term studies. The coagulation of blood is usually reduced by binding calcium ions in so-called calcium citrate chelates by adding citrate in the extracorporeal blood circulation upstream of the dialyzer. In some cases, these calcium citrate chelates are again infused into the patient with the return of blood, where the citrate component is metabolized in the liver and calcium is again released. Another part of the chelate is removed from the extracorporeal blood circulation by the dialyzer membrane and discarded.

Since patients lose a significant amount of calcium during this process, calcium can be added manually prior to blood reinfusion. The rate of citrate addition is typically related to the blood flow rate in order to provide sufficient anticoagulation for a corresponding amount of blood in contact with the components of the extracorporeal blood circulation. The rate of calcium addition may be selected so as to compensate for calcium loss through the dialyzer membrane. It is therefore related to the blood flow through the dialyzer, but also to a number of other parameters, such as the rate of addition of citrate and the individual characteristics of the treatment process (e.g. choice of dialyzer membrane, main transmembrane pressure), etc.

Thus, the concentration of calcium ions can be monitored periodically by sampling during Ci-Ca CRRT, and the addition rate can be corrected accordingly. However, the experience of the above-mentioned studies can also be utilized in addition; these studies were conducted using standard protocols for Ci-Ca dosages available to the user. To this end, control means may be provided to control the respective addition of the anticoagulant substance. This control may be implemented, for example, based on at least one or more of the following variables described above: calcium ion concentration, blood flow rate, dialyzer membrane, transmembrane pressure, and/or standard protocols stored in the device.

If another extracorporeal blood treatment is added to the combined extracorporeal blood circulation for acute dialysis, the result may be some completely new boundary conditions regarding the dosing of citrate and calcium in Ci-Ca anticoagulation. In particular, since the influence of the blood treatment element on the coagulation stimulation and any calcium loss in the dialyzer other than that known is not taken into account, the dosing regimen established by the long-term results of the study of the dialyzer and the blood treatment element in series is not necessarily accepted for further extracorporeal treatment.

The line guiding structure according to the invention optionally makes it possible to arrange an injection port for delivering a first medical fluid for anticoagulation (e.g. citrate) in a section of the main blood line upstream of the dialyzer, the total blood flow in said section then also going through the dialyzer. Thus, one can continue to use the known dosing regimen for Ci-Ca anticoagulation despite the combination therapy, since only the coagulation of the dialyzer needs to be considered initially. The components of the blood treatment element may be treated with an anticoagulant via the coating.

Furthermore, the line guiding structure optionally makes it possible to arrange an injection port for adding a second medical fluid for anticoagulation (e.g. calcium) to the main blood line downstream the blood treatment element.

In an additional embodiment of the invention, where the first branch point is arranged upstream of the dialyzer, thus the first injection port for the first medical fluid is located downstream of the first branch point, an additional injection port for a third medical fluid for anticoagulation (e.g. citrate) may be arranged upstream of the first branch point. If desired, an increased anticoagulant effect can be produced simply in the whole extracorporeal blood circulation by further adding citrate, preferably a small amount of citrate, through the line. For small amounts of citrate, it is preferred to add further citrate through the injection port upstream of the first branch point, since the maximum amount of citrate tolerated is metabolically limited and requires a greater effect on the dialyzer, which usually does not have an anticoagulant coating. Therefore, even if a small amount of citrate is further added through the line when calcium is given, it is not necessary to deviate from the known algorithm in this case.

The first and/or second and/or third medical fluid used for anticoagulation may also be heparin or some other medical fluid having an anticoagulation effect.

A pump section for an infusion pump with which the respective fluid to be added can be transported from the reservoir through the supply line to the main blood line is provided, for example, in some or all of the above-mentioned injection ports for calcium or citrate. In embodiments where the same medical fluid is delivered through multiple supply lines (particularly in the case of citrate), a common pump and/or fluid from a common reservoir may also be used.

For determining the transmembrane pressure, the blood treatment device can have a pressure sensor as described above, in particular for measuring the pressure in the main blood line between the dialyzer and the blood treatment element, wherein a corresponding pressure measurement section for determining the pressure by means of the pressure sensor can be provided in some embodiments in the blood conducting device.

The blood treatment device can have an additional pressure sensor for determining the transmembrane pressure, in particular for measuring the pressure in the main blood line between the first branch point and the dialyzer. A corresponding pressure measuring section for determining the pressure by means of a pressure sensor may be provided at the above-mentioned location.

Two or more pressure sensors may also be provided at other locations for measuring pressure at the two locations or at other locations. This allows a particularly accurate determination of the transmembrane pressure and a better monitoring of the treatment process by means of a corresponding limit value window of pressure values.

One or more pressure sensors may be provided on the dialysate side for measuring transmembrane pressure. Thus, the pressure can be measured on the dialysate side upstream and/or downstream of the dialyzer.

In order to also allow a combined treatment with a method of hemofiltration or hemodiafiltration in connection with renal replacement therapy, the blood guiding device may optionally also comprise one or more injection ports for dilution fluid on the main blood line. Through these injection ports, a dilution fluid, for example a replacement solution or a dialysis solution, can be conveyed into the main blood line through these injection ports by means of corresponding infusion pumps on the blood treatment apparatus side. The present invention may also optionally include one or more reservoirs for storing the diluting fluid, e.g., a disposable bag. Alternatively, the blood treatment device can also be equipped to prepare a replacement solution and/or a dialysis solution. For this purpose, the blood treatment device can have a water treatment device, for example with a degassing device, and a concentrate port for connecting a concentrate source. An injection port for dilution fluid may be provided on the main blood line upstream of the dialyzer for pre-dilution. For post-dilution, an injection port for the dilution fluid may be provided downstream of the dialyzer and upstream of the blood treatment elements. In the case of the combination therapy of the invention using a dialyzer and a blood treatment element, there is also another possibility of post-dilution. An injection port for post-diluted dilution fluid may also be provided in the main blood line downstream of the blood processing element. The introduction of a replacement, generally containing calcium, downstream of the blood treatment element has the following advantages: the anticoagulant effect of citrate occurs in the most extensive possible component of the extracorporeal blood circulation.

The user may also optionally connect the replacement line to one or more of the above-described injection ports for the dilution fluid. The dilution fluid may also be delivered from a common reservoir and/or by means of a common infusion pump.

Drawings

The invention will now be described in more detail below on the basis of exemplary embodiments and the figures.

In these drawings:

fig. 1 shows a schematic view of an embodiment of a blood treatment system according to the invention.

Fig. 2 shows a schematic view of an embodiment of a blood guiding device according to the invention comprising a connected dialyzer and a connected blood treatment element.

FIG. 3 a: the blood conducting device according to the invention is shown in a schematic flow diagram.

FIG. 3 b: the blood conducting device shown in fig. 3a is shown in a schematic flow diagram with additional optional components.

FIG. 4 a: an alternative embodiment variant of the pump arrangement is shown in a flow path diagram as an example, represented by a pump arrangement section.

FIG. 4 b: a further alternative embodiment variant of the pump arrangement, which is represented by a pump arrangement section, is shown in a flow path diagram as an example.

FIG. 4 c: a further alternative embodiment variant of the pump arrangement, which is represented by a pump arrangement section, is shown in a flow path diagram as an example.

FIG. 4 d: a further alternative embodiment variant of the pump arrangement represented by the pump arrangement section is shown in a flow path diagram.

FIG. 5 a: a blood guiding device according to the invention in an alternative embodiment is shown in a schematic flow diagram.

FIG. 5 b: the blood conducting device shown in fig. 5a is shown in a schematic flow diagram with additional optional components.

FIG. 6 a: a further alternative embodiment of the blood guiding device according to the invention is shown in a schematic flow diagram.

FIG. 6 b: the blood guide device flow diagram shown in figure 6a is shown in a schematic flow diagram with an alternative arrangement of recirculation return ports.

FIG. 7: the blood conducting device shown in fig. 6a is shown in a schematic flow diagram with additional optional components.

Detailed Description

As shown in fig. 1, blood processing system 1000 includes blood processing apparatus 10 and blood introducing apparatus 100. Fig. 1 shows a blood treatment device 10 in the form of a dialysis machine for acute dialysis, which is equipped with a blood conducting device 100 designed as a cassette. The blood treatment device has a control device 30 and a pump arrangement 7. Fig. 1 furthermore shows a main blood line 101 of the blood conducting device 100, to which main blood line 101 a dialyzer 102 and a blood treatment component 103 in the form of a gas exchanger are connected. The main blood line 101 may also have one or more pressure measurement sections, at which the pressure can be determined by means of the pressure sensor 17 optionally present in the blood treatment device 10.

According to the invention, the blood guiding device 100 can be designed as a disposable item for medical use in the form of a blood cassette (fig. 2). The blood guiding device 100 may have one or more pump arrangement sections 107, which pump arrangement sections 107 the pump arrangement 7 of the blood treatment device 10 may act on to convey fluid in the respective line sections of the blood treatment device 100. Fig. 2 shows a main blood line 101 branching off from the cassette of the blood conducting device 100, in which a pump arrangement section 107 can be arranged, and then recirculated back to the cassette, which comprises a dialyzer 102 in series and a blood treatment element 103, here in the form of a gas exchanger. A first branch point 104 from which a first secondary line 106 branches may be disposed upstream of dialyzer 102. A second branch point 105, where the first secondary line 106 joins the main blood line 101 again, can be arranged downstream of the dialyzer 102 and upstream of the blood treatment element 103. Furthermore, an injection port 108 for anticoagulated first medical fluid (e.g. citrate) may be provided upstream of the dialyzer 102. Downstream of the blood treatment element 103, a recirculation branch point 119 can be provided, from which recirculation branch point 119 a second secondary line 120 branches off. The second secondary line 120 leads to a recirculation return port 121, which recirculation return port 121 may be disposed in the main blood line 101 upstream of the blood treatment element 103 and downstream of the dialyzer 102.

Blood directing device 100 has a primary blood line 101, wherein primary blood line 101 has a blood withdrawal port 127 at one end for connection to a patient's blood withdrawal pathway and a blood return port 128 at the other end for connection to a patient's blood return pathway. In the main blood line 101, the blood withdrawn from the patient can be sent in an extracorporeal circuit to the dialyzer 102 and to the blood treatment unit 103 for further extracorporeal blood treatment treatments and be infused back into the patient, as schematically shown in the flow diagram in fig. 3 a.

A dialyzer 102 is disposed in the main blood line. It usually has a blood chamber and a dialysate chamber (not shown here), wherein the two chambers are separated by a semipermeable membrane through which the blood can osmotically interact with a dialysis solution flowing in a dialysate circuit. The dialyzer according to the invention can also be used for other kidney support and/or kidney replacement treatments commonly used in dialysis, such as hemodiafiltration, hemodialysis, hemoperfusion, hemofiltration, ISO-UF and the like, in particular also for treatment methods in which no dialysis solution is delivered on the dialysate side.

Downstream of dialyzer 102, main blood line 101 carries blood through a blood treatment element 103, which is designed here as a gas exchanger. The blood treatment element 103 has a blood chamber and a gas chamber (not shown here), wherein the two chambers are separated by a semi-permeable membrane through which blood can osmotically interact with the gas flowing in the gas line.

Dialyzer 102 and gas exchanger 103 may have a plurality of individual membranes in the form of hollow fibers. The individual chambers for blood, dialysate or gas in the sense of the present invention can also consist of a plurality of individual volume spaces which are located within the hollow fibers and are fluidically connected to one another at the ends of the fibers.

Upstream of dialyzer 102, main blood line 101 has a first branch point 104. From this first branch point 104, a first secondary line 106 leads to a second branch point 105 of the main blood line 101.

Furthermore, the blood conducting device has a pump arrangement section 107, to which pump arrangement section 107 blood can be conveyed by means of the pump arrangement 7 of the blood treatment device 10 via the main blood line 101 and also via the first secondary line 106. In the exemplary embodiment shown in fig. 3a, the first pump arrangement 7 is shown in the form of two occlusive blood pumps, one blood pump being located in the main blood line 101 upstream of the first branch point 104, the second blood pump being located in the main blood line 101 downstream of the first branch point 104 and upstream of the dialyzer 102. In the present exemplary embodiment, for example, the first pump delivers fluid at a rate of 500mL/min, while the second pump delivers fluid only at a rate of 200 mL/min. Thus, a flow rate of 300mL/min is established in secondary line 106. A blood flow rate of 200mL/min is established on dialyzer 102, while gas exchanger 103 has a flow rate of 500mL/min through it, since the two partial flows of 200mL/min and 300mL/min are merged at second branch point 105.

As schematically shown in fig. 3b, the blood conducting device may optionally be provided with an injection port for anticoagulated medical fluid. Thus, an injection port 108 for citrate solution may be provided downstream of the first branch point 104 and upstream of the dialyzer 102. The injection port may also be designed as a citrate line 108, which is connected to a citrate reservoir 109. Furthermore, the blood treatment device 10 may have an infusion pump 110 designed to deliver citrate from the reservoir 109 into the main blood line 101 through the injection port 108. An injection port 111 for the calcium solution may also be provided downstream of the blood processing component 103. The injection port may also be designed as a calcium line 111, which is connected to a calcium reservoir 112. Furthermore, the blood treatment device 10 may also have a further infusion pump 113, which is designed to transport calcium from the reservoir 112 into the main blood line 101 via the access port 111.

Figure 3b also shows an alternative citrate addition possibility. Thus, a third injection port 114 for anticoagulated medical fluid is provided upstream of the first branch point 104 in the main blood line. The injection port 114 may also be designed as a transfer line, which may be connected to a citrate reservoir 115. Furthermore, the blood treatment device 10 may also have a further infusion pump 116, which is designed to transport citrate from the reservoir 115 through the third transport line 114 into the main blood line 101. Alternatively, the third transfer line 114 may also be supplied from the first reservoir 109 (not shown here). Furthermore, as an alternative, the third infusion pump 116 may be omitted if the pressure generated by the first infusion pump 110 is used in a third delivery line branching off from downstream. For this purpose, the third feed line can have a valve or throttle arrangement which adjusts the pressure accordingly.

Fig. 4a to 4d schematically show details of the main blood line 101 of the blood guiding device 100 in the region around the first branch point 104 and the second branch point 105, respectively, which details in this embodiment comprise two flow paths through the secondary line 106 and through the section of the main blood line 101 that passes the dialyzer 102. Fig. 4a to 4d show examples of various possible embodiments of pump arrangements, represented by

pump arrangement sections

207, 307, 407, 507 for the action of the pump arrangement 7 of the blood treatment apparatus 10.

Whereas the pump configuration of the embodiment shown in fig. 3a, represented by pump configuration section 107, has an occlusion blood pump located in main blood line 101 upstream of first branch point 104 and another occlusion blood pump located in main blood line 101 between dialyzer 102 and first branch point 104, fig. 4a shows a variant of the pump configuration represented by pump configuration section 207, which pump configuration section 207 also has a first blood pump located in main blood line 101 upstream of first branch point 104, but instead an additional occlusion blood pump is arranged in secondary line 106.

In the example of the pump configuration shown in fig. 4b and 4c, represented by

pump configuration sections

307, 407, the additional blood pump in secondary line 106 and/or in main blood line 101 between dialyzer 102 and first branch point 104 has been replaced by a restriction element, respectively.

Fig. 4d shows another exemplary embodiment of the first pump configuration, represented by pump configuration section 507, comprising two occlusion blood pumps, one of which is arranged in the secondary line 106 and the other of which is located between the dialyzer 102 in the main blood line 101 and the first branch point 104.

All pump configurations according to the invention can both generate a blood flow in the main blood line 101 and also carry a partial flow through the secondary line 106 at a defined flow rate, so that the ratio between the total flow in the main blood line 101 upstream of the first branch point 104 and/or downstream of the second branch point 105 and the total flow in the region of the dialyzer 102 is adjustable. The invention is not limited to the embodiment of the pump arrangement 7 shown in fig. 4a to 4 d. As will be appreciated by those skilled in the art, there are many other possibilities in the prior art to control the flow rate ratio in the two line sections. In many embodiments, the pump arrangement 7 can control the flow rates of the two line sections independently of each other. The pump arrangement 7 may have a variety of fluid components including occlusive, non-occlusive, clamps, valves, throttling arrangements, and the like. The components of the pump arrangement 7 may also be arranged at other locations in the extracorporeal blood circulation or may be active at those locations.

As schematically shown in fig. 5a on the basis of a flow diagram, the blood guiding device 100 may also have alternative flow guiding structures. In this example, a first branch point 104 at which the secondary line 106 branches off from the primary blood line 101 is provided downstream of the blood treatment element 103. Furthermore, in the present example, a second branch point 105, at which the secondary line 106 joins the primary blood line 101 again, is provided upstream of the blood treatment element 103 and downstream of the dialyzer 102.

As schematically shown in fig. 5b, the blood conducting device may optionally be provided with an injection port for anticoagulated medical fluid. Thus, an injection port 108 for citrate solution may be provided upstream of dialyzer 102. The injection port may also be implemented as a citrate line 108, which is connected to a citrate reservoir 109. Furthermore, the blood treatment device 10 may also have an infusion pump 110, which is designed to transport citrate from the reservoir 109 into the main blood line 101 through the injection port 108. An injection port 111 for a calcium solution may be provided downstream of the blood processing component 103. It may also be designed as a calcium line 111 connected to a calcium reservoir. Furthermore, the blood treatment device 10 may also have an additional infusion pump 113, which is designed to transport calcium from the reservoir 112 into the main blood line 101 via the calcium line 111.

Fig. 6a schematically shows a further alternative embodiment of the blood conducting device according to the invention on the basis of a flow diagram, wherein, in addition to the features of fig. 3a, there is also a second secondary line 120 for repeatedly recirculating blood through the blood treatment element 103, which is designed here as a gas exchanger. A secondary line 120 leads from the recirculation branch point 119 of the main blood line 101 and leads to a recirculation return port 121. In the example of fig. 6a, a recirculation return port 121 is provided in the first secondary line 106 upstream of the second branch point 105. The example in fig. 6b shows an alternative line guiding structure in this respect and differs from the embodiment shown in fig. 6a in that a recirculation return port 121 is provided in the main blood line 101 directly downstream of the dialyzer 102 and upstream of the blood treatment element 103. In the embodiment of fig. 6a and 6b, the pump arrangement 7 of the blood treatment device 10 may also be equipped for generating a blood flow in the secondary line 120. For this purpose, the pump arrangement 7 of the blood treatment device 10 in fig. 6a and 6b (here represented by the pump arrangement section 107) comprises an additional occlusion pump in the second secondary line 120. Furthermore, the control device 30 of the blood treatment device 10 may be designed to operate the pump arrangement 7 such that the blood flow rate in at least one section of the primary blood line 101 is independent of at least one of the blood flow rates in the

secondary lines

106, 120.

Fig. 7 schematically shows an embodiment of the blood guiding device of fig. 6a with additional optional components. The

injection ports

108, 111, 114 and the corresponding infusion pumps 110, 113, 116 and

reservoirs

109, 112, 115, which have already been described for the exemplary embodiment in fig. 3b, can also be provided in an embodiment with two

secondary lines

106, 120.

Fig. 7 also shows two optional

pressure measurement sections

117, 118 in main blood line 101 downstream and upstream of dialyzer 102. First, the pressure downstream of the dialyzer and optionally also upstream of the dialyzer helps to determine the transmembrane pressure. This is an important variable, for example, it provides information about an impending filter blockage during a dialysis treatment. Transmembrane pressure may also be considered in determining the calcium delivery rate via the second injection port 111. Secondly, the pressure in the respective flow section also contributes to monitoring the process by means of the pressure limit value window.

In addition, fig. 7 also shows optional components that allow hemofiltration and/or hemodiafiltration to also occur in connection with renal replacement therapy. For this purpose, the extracorporeal blood circuit may have one or

more injection ports

124, 125, 126 for dilution fluid, which are optionally also designed as a replacement line, through which replacement fluid from the reservoir 122 can be conveyed into the main blood line 101 by means of a further infusion pump 123. The substituate line can also be connected in a pre-dilution 124 and then lead into the main blood line 101 upstream of the dialyzer 102. The displacer line can also be connected during post-dilution. In post-dilution, the blood circulation device according to the invention provides two possible connection locations. In a first option, post-dilution line 125 may open into primary blood line 101 between dialyzer 102 and blood treatment element 103. In a second option, the post-dilution line 126 may also open into the main blood line 101 downstream of the gas exchanger. The last variant 126 offers the advantage that the replacement solution, which usually contains calcium, reduces the anticoagulation effect of citrate only partly after the extracorporeal blood circulation.

Alternatively, the displacement line may also be connected intentionally by the user to one or more than two of the above-mentioned positions. In a combination of pre-dilution and post-dilution, two infusion pumps pumping fluid independently of each other may optionally also be used for diluting the fluid (not shown).

The blood treatment device 10 includes a control device 30. The control device 30 may be configured to control and regulate the process. According to one method covered by the invention, in all embodiments, a blood flow rate of between 0 and 300mL/min can be generated in the main blood line 101 in the region of the dialyzer 102 by means of the pump arrangement 7. Furthermore, blood flow rates in excess of 500mL/min may be produced in the region of the blood treatment element 103. In the example of fig. 3a and 3b, the flow rate in the main blood line 101 upstream of the first branch point 104 corresponds to the flow rate in the blood treatment element 103. The desired dialysate flow rate can be adjusted by means of the pump arrangement 7. This causes the flow rate in the secondary line 106 to be the difference between the flow rate in the blood treatment element 103 and the dialyzer flow rate.

The flow rate in the blood processing element 103 may also be greater than 800mL/min, greater than 1L/min, or greater than 2L/min in all embodiments of the invention. The ECMO method is typically used at blood flow rates up to 8L/min. According to the invention, all these flow rates and even higher flow rates are possible in the region of the blood treatment element 103, which is designed, for example, as a gas exchanger.

In all embodiments, the dialyzer flow rate may also be in the range between 100 to 250 mL/min. It may also be in the range of 175 to 225mL/min, or may be just 200 mL/min.

The flow rate of the first medical fluid for anticoagulation (e.g. citrate) pumped into the main blood line 101 by means of the first infusion pump 110 may be adjusted by the control device 30 depending on the dialyzer flow rate.

The flow rate of the second medical fluid for anticoagulation (e.g. calcium) pumped into the main blood line 101 by means of the second infusion pump 113 may be adjusted by the control device 30 depending on the dialyzer flow rate. The adjustment may additionally take into account other relevant factors, such as the flow rate of the first medical fluid for anticoagulation, the flow rate of the third medical fluid for anticoagulation, the TransMembrane Pressure (TMP), the type of dialyzer and/or other parameters, optionally also those to be selected or input by the user.

The flow rate of the third medical fluid for anticoagulation (e.g., citrate) may be controlled by the user through direct selection. It may also be adjusted based on the flow rate in the blood treatment element 103, or may be adjusted based on the difference between the flow rate in the blood treatment element 103 and the dialyzer flow rate.

Claims

1. A blood treatment device (10) for performing an extracorporeal blood treatment, in which blood treatment device (10) the blood is conducted in a blood conducting device (100) having a main blood line (101) and at least one secondary line (106), which secondary line (106) is fluidly connected to the main blood line (101), wherein the main blood line (101) has a dialyzer (102) and downstream of the dialyzer (102) has a blood treatment element (103), wherein the blood treatment device (10) has:

-a control device (30); and

a pump arrangement (7) equipped for generating a blood flow in the primary blood line (101) and in the at least one secondary line (106),

wherein the control device (30) is configured to be able to operate the pump arrangement (7) such that a first blood flow rate in the dialyzer (102) is decoupled from a second blood flow rate in the blood treatment element (103).

2. The blood processing device (10) according to claim 1,

wherein the pump arrangement (7) is designed to generate an independent blood flow rate in the primary blood line (101) and in the at least one secondary line (106).

3. Blood treatment device (10) according to one of the preceding claims,

wherein the extracorporeal blood guiding device (100) further has a secondary line (120) fluidly connected to the primary blood line (101);

wherein the pump arrangement (7) is further equipped for generating a blood flow in the second secondary line (120); and

wherein the control device (30) is configured to be able to operate the pump arrangement (7) such that the blood flow rate in at least one section of the primary blood line (101) is independent of at least one of the blood flow rates in the secondary lines (106, 120).

4. Blood treatment device (10) according to claim 1 or 2,

wherein the blood treatment device (10) comprises:

-an infusion pump (110) for supplying a medical fluid into the main blood line (101);

or

-two infusion pumps (110, 113) for supplying medical fluid into the main blood line (101); or

-three infusion pumps (110, 113, 116) for supplying medical fluid into the main blood line (101); or

-four or more infusion pumps (110, 113, 116, 123) for supplying medical fluid into the main blood line (101).

5. Blood treatment device (10) according to claim 4,

wherein the control device (30) is configured to adjust the delivery rate of at least one of the infusion pumps in dependence on the blood rate in the dialyzer (102).

6. The blood processing device (10) according to any one of claims 1, 2, 5,

wherein the blood treatment device (10) has a pressure sensor (17) for determining the pressure in the main blood line (101) downstream of the dialyzer (102) and upstream of the blood treatment element (103).

7. Blood treatment device (10) according to claim 5,

wherein the control device (30) is configured to be able to adjust the delivery rate of at least two of the infusion pumps individually depending on the blood flow rate in the dialyzer (102).

8. A blood guiding device (100) for cooperation with a blood treatment device (10) according to any one of the preceding claims,

the blood guiding device (100) comprises:

-a main blood line (101) for fluid connection to a dialyzer (102) and for fluid connection to a blood treatment element (103) downstream of the dialyzer (102), wherein the main blood line (101) has a blood withdrawal port (127) at one end for connection to a blood withdrawal pathway of a patient and a blood return port (128) at the other end for connection to a blood return pathway of a patient;

-at least one secondary line (106) branching from the primary blood line (101) at a first branch point (104) and rejoining the primary blood line (101) at a second branch point (105); and

-one or more pump arrangement sections (107) designed for the action of a pump arrangement (7) on a blood treatment device (10).

9. Blood guiding device (100) according to claim 8,

wherein the first branch point (104) is arranged upstream of the connection point for the dialyzer (102); and

wherein the second branch point (105) is arranged downstream of the connection point for the dialyzer (102) and upstream of the connection point for the blood treatment element (103).

10. Blood guiding device (100) according to claim 8,

wherein the first branch point (104) is arranged downstream of a connection point for the blood treatment element (103); and

wherein the second branch point (105) is arranged upstream of the connection point for the blood treatment element (103) and downstream of the connection point for the dialyzer (102).

11. Blood guiding device (100) according to claim 8,

the blood guiding device (100) comprises a secondary line (120) branching off from the main blood line (101) at a recirculation branch point (119) and leading to a recirculation return port (121);

wherein the second branch point (105) is arranged downstream of the connection point for the dialyzer (102) and upstream of the connection point for the blood treatment element (103); and

wherein the recirculation branch point (119) is arranged downstream of a connection point for the blood treatment element (103); and

wherein a recirculation return port (121) is provided in the main blood line (101) upstream of the connection point for the blood treatment element (103) and downstream of the connection point for the dialyzer (102); or

Wherein the recirculation return port (121) is provided in the secondary line (106) upstream of the second branch point (105).

12. Blood guiding device (100) according to one of the claims 8 to 11,

wherein the main blood line (101) comprises:

-an injection port (108) for anticoagulated first medical fluid upstream of the connection point for the dialyzer (102); and/or

-an injection port (111) for an anticoagulated second medical fluid downstream of the connection point for the blood treatment element (103).

13. Blood guiding device (100) according to claim 9 or 11,

wherein the main blood line (101) comprises:

-an injection port (108) for anticoagulated first medical fluid downstream of the first branch point (104) and upstream of the connection point for the dialyzer (102); and/or

-an injection port (111) for an anticoagulated second medical fluid downstream of the connection point for the blood treatment element (103); and/or

-an injection port (114) for anticoagulated third medical fluid upstream of the first branch point (104).

14. Blood guiding device (100) according to one of the claims 8 to 11,

wherein the main blood line (101) has a pressure measurement section (117) for determining the pressure in the main blood line (101) downstream of the connection point for the dialyzer (102) and upstream of the connection point for the blood treatment element (103).

15. Blood guiding device (100) according to one of the claims 8 to 11,

wherein the main blood line (101) comprises:

-an injection port (124) for dilution fluid upstream of the connection point for the dialyzer (102); and/or

-an injection port (125) for a dilution fluid downstream of the connection point for the dialyzer (102) and upstream of the connection point for the blood treatment element (103); and/or

-an injection port (126) for a dilution fluid downstream of a connection point for the blood treatment element (103).

16. Blood guiding device (100) according to one of the claims 8 to 11,

wherein the blood guiding device (100) comprises a dialyzer (102) and a blood treatment element (103).

17. Blood guiding device (100) according to claim 16,

wherein the blood treatment element (103) is a gas exchanger.

18. A blood processing system (1000) comprising:

-a blood treatment device (10) according to any one of claims 1 to 7; and

-a blood guiding device (100) according to any of claims 8 to 17.